Process for the production of photolike multitoned prints



March 9, 1937.

F. LIERG PROCESS FOR THE PRODUCTION OF PHOTO-LIKE MULTITONED PRINTS Filed March 15, 1934 while the tones are of copying on development paper.

30 paper, so that during the following 45 ical manner.

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE PROCESS FOR THE PR ODUCTION F PHOTO- LIKE MULTITONED PRINTS Friedrich Lierg,

of Switzerland Application March 15,

Vienna, Austria, Jasma A. G., Zurich,

assignor to Switzerland, a company 1934, Serial No. '715,719

In Germany March 17, 1933 1 Claim.

Pictures, which cannot be distinguished from photographs, can be produced by the socalled suction method in which are used printing matrices consisting of colloidal substances either in the shape of an image relief or in the form of a produced in a less expensive manner and that it is possible to select practically unlimited tones,

limited which can be obtained by the chemical toning of the silver images. Therefore the tone can be adapted to the characteristic of the picture and to the taste of the purchaser.

In the known suction printing methods, such as the pinatype, the Jos-Pe method and the like, in which the printing matrices are produced by the action of light, the time required for printing is very considerable in View of the slow transmission of the coloring matter, and therefore :these methods cannot compete in the case of the production in large quantities with the method However besides this fact, they are not adapted for the pro duction of series in diiierent tones of colors, because during printing the entire coloring matter does not pass from the matrix into the printing printing with another color the remainder of the coloring matter participates in the printing to a considerable extent and therefore influences the intended color tone in an incontrollable and frequently dis- 35 advantageous manner.

In view thereof it is necessary to take for every coloring matter a separate matrix or to work with color-destroying agents which however unfavorably influence the matrix.

, Lately the suction method has been improved considerably, so that the printing operation is carried out in a few seconds and consequently the production in large quantities of monochrome or multi-tone prints is carried out in an econom On the other hand by the idea of preparing the printing layer of the printing paper in such a manner that the dyestufi or any other coloring agent is precipitated in a water-insoluble manner when passing into this layer, it has been 50 possible to transmit the entire dyestuif or coloring agent, imbibed in the matrix, from the latter, so that no residue of coloring matter remains behind which may detrimentally influence a print carried out in another color.

55 Applicable for the process according to the present invention are particularly those suction printing methods in which, by a particular preprelief or by a particular water-insoluble manner and are set free again by the special preparation of the printing paper only, because the coloring is effected in a very short time by the artificially produced or already originally effective afiinity between the gelatinerelief and the dye, so that also this procedure is carried out very quickly.

Also inorganic and organic electrolytes particularly metallic salts are absorbed very quickly by the gelatine-relief. If the printing paper is prepared in known manner with a precipitant for the metallic salt which jointly result in a correspondingly colored precipitate, the entire metallic salt solution is transmitted from the relief durmg the printing, so that printing can take place immediately with another metallic salt without the use of any intermediate washing.

An apparatus for carrying out the process according to the present invention is shown diagrammatically and by way of example in the accompanying drawing. The printing matrices used for this object can be produced either by the tanning development of exposed haloid silver emulsions for instance by means of pirochatechine or by the action of a hardening bleacher and by washing in hot water. Also chromate gelatine layers can be hardened in picture-like manner by exposure behind a diapositive. These are a few examples only which are suitable for the production of printing matrices and do not form an essential part of the present invention.

As shown in the drawing, an endless band I of a flexible material, for instance a metal tape, celluloid band or the like, is provided with printing matrices. The band I is led over rollers 2, 3, 2', 3', 4', 5', 6', 1', 8, 4, 5, 6, 1, 8 and passes through four troughs 9, I0, 9', l The troughs 9 and 9 are filled with solutions of for instance basic dyes for coloring the matrices, while the troughs Ill and I9 contain water for washing away the dye in excess. The printing paper II is coated with a gelatine layer containing a precipitant for the dye (for instance silico tungstic acid) and is in the form of a long band, which is wound up on a roller l2 and passes over rollers l3, I4 and through a trough l9 filled with water for wetting the band II. The bands I and H are brought into intimate contact with each other between the rollers 2 and and I6, and 3 and I1, whereby the entire dye contained in the matrices of the band I is transplied with the other dye,

mitted to the layer of the printing paper, because it is precipitated in the same in a water insoluble manner. After leaving the rollers 3 and I1, the band I returns into the trough 9, while the paper-band H is wound up on a roller l8. Thus the entire dye is removed from the matrices before they return into the trough 9 and therefore the latter can be filled without difiiculty with another dye without the danger of obtaining mixed colors such as it is the case for instance in connection with the known pinatype process. The dyeing of the matrices takes approximately one half minute, while the complete transmission of the dye from the matrix takes approximately one minute, and therefore provision is made that each matrix remains in the troughs 9 and 9 for approximately one half minute, while double the time is taken by the matrix during its movement with the printing paper between the rollers 2 and 3. For printing in two tones, thus pictures with soft lights and intense shades, use is made of the arrangement in the following manner. The trough 9 is charged with a basic dye for making the shades. The trough 9 is filled with dye for printing the lighter places. The rinsing water in the trough I0 is slightly acidified. A part of the dye of the matrix is again removed in the trough 16'. This removal influences mainly the thin places of the lights, so that essentially the shades are printed only. Now the band I passes over the roller 20 and into the trough 9 in which'the matrices are supwhich mainly determines the tone of the lights. In the trough ID, the excessive dye is washed by water, which produces an alkaline reaction and therefore does not set free the basic dye in the gelatine but rather promotes the binding thereof.

If desired, a mixture of two dyes, for instance rhodolinreinblau (Zeitschrift fiir Farbenund Textilchemie 1903, page 337, published by Wieweg und Sohn, Braunschweig, Germany) and chrysoidin (Schultz No. 33), is charged into the trough 9', the dye (rhodolinreinblau) determining the tone of the shades being readily removed by washing, while the other dye (chrysoidin) belongs to that group of basic dyes which together with the gelatine of the printing matrix form a completely waterproof combination. One of the dyes is washed out of the thin places of the picture in the trough it), so that these places print only the tones of the other dye, while the shadetones are determined mainly by the more readily washed out dye or by the mixture of both dyes. In this case the arrangement 2 to 10 is not in use or it can be used as a separate printing device provided with its own paper-feed.

The trough Ill is filled, for instance, with p0- tassium ferrocyanid, while the troughs 9, 9' and I0 remain unused, if electrolytic solutions are used for printing. In this case a water bath is not used for removing the adhering solution, because the same would completely wash out the electrolytic solution from the matrix. The adhering solution is removed for instance by elastic wipers 2|, disposed between the rollers 8 and 2. Similar wipers 22 are arranged for removing any adhering water from the paper II between the rollers I4 and I5. The colloidal layer of the paper is treated for instance with a ferric salt and uranates. This results in pictures ranging from olive-brown to olive-green, the shades being more brownish and the lights more bluish. A printing paper with two layers, each containing different precipitants, results in the production of double tones. If the bottom layer contains for instance a ferric salt and in case the top layer embodies a certain quantity of a uranate and if potassium ferrocyanide is used for printing, the result will be a reaction of the entire potassium ferrocyanide with the uranate in the light places of the picture, so that brownish lights are produced. In the dark parts of the shades, the matrices contain such a quantity of potassium ferrocyanide that the same does not fully react with the limited quantity of uranate. The rest of potassium ferrocyanide reacts with the ferric salt of the bottom layer and forms Prussian blue which transforms the brown of the shades into a black or bluish black tone.

In all cases, the printing can be carried out according to the described methods also by other arrangements or even by hand. In view of the ready application of the coloring agent it is not necessary to bathe the matrix in the solution,

but the same can be applied to the matrix by means of a brush, cotton or the like if necessary by the aid of stencils, so that the individual parts of the picture can be made in different tones of color. tone prints can be influenced at individual places by the application of color.

What I claim is Process for the production of photo-like multi-toned prints by means of a gelatin matrix and by using a printing surface prepared with a reagent which precipitates coloring agents in a water-insoluble form, which consists in first applying two coloring agents precipitatable by said reagent to the matrix, one of said coloring agents being irremovable while the other coloring agent is removable by washing, thenpartly removing said removable coloring agent, hereafter placing in contact said printing'surface with said matrix whereby both coloring agents are from said matrix to said printing surface, and finally separating said matrix and said printing surface.

FRIEDRICH LIERG.

Matrices prepared for single or multi- 4 transferred 

